The present invention relates to an orthodontic-loop applicator tool, and more particularly, to a tool for use with an orthodontic loop chain.
A common type of orthodontic apparatus employs metal bands which are mounted, as by cementing, on a person's teeth. Each band is provided with a bracket which receives an archwire that is adapted to be attached to the tooth-mounted brackets to produce tooth-positioning forces. In recent years, elastomeric loops have become a popular type of ligature for fastening an archwire to such an orthodontic bracket.
In my copending patent application, Ser. No. 344,292, filed Feb. 1, 1982, for "ORTHODONTIC ELASTOMER CHAIN WITH CONTROLLED BREAKAWAY ISTHMUSES", I disclose an orthodontic loop chain for facilitating dispensing and attaching orthodontic loops individually to orthodontic tooth appliances. The chain is composed of a series of elastomeric loops connected by breakaway isthmuses which allow chain loops to be detached as individuals by a sharp pulling force which breaks an isthmus.
The present invention contemplates a tool which is especially adapted for use in dispensing and clamping the loops in such a chain in a loop-by-loop manner to permit their placement as individuals on different ligating brackets.
Accordingly, a general object of the present invention is to provide an applicator tool for use in dispensing and clamping the loops in such a chain in a manner which allows the loops to be installed readily and conveniently, loop-by-loop.
Another object of the invention is to provide such a tool which is manipulatable both to fasten the loops in such a chain to a tooth bracket, and to advance the chain, loop-by-loop, in an indexed manner.
The tool of the present invention is intended for use with an orthodontic loop chain composed of a series of elastomeric loops linearly connected by breakaway isthmuses. The tool includes a pair of loop-gripping tips adapted for clamping an end loop in the chain in a manner permitting the clamped loop to be placed on a bracket to secure an archwire thereto. The tool includes structure defining a path along which the chain is intended to be advanced in a forward direction toward the tips. A constriction zone formed in this path, adjacent its downstream end, functions to restrain successive chain loops at positions where successive end loops are placed for clamping between the tool tips. The chain is advanced along the path, in a loop-by-loop manner, by exerting a force on the chain in a downstream direction, to pull the restrained chain loop through the constriction zone by reversible loop elongation.
These and other objects and features of the present invention will become more fully apparent when the following detailed description of a preferred embodiment of the invention is read in connection with the accompanying drawings.